The T-Post Pinlock insulator by Power Wizard can be used with standard smooth wires, stranded wires or polywire on a T-post. The insulator has a large flange to prevent shorts and is made of black high-density polyethylene. The insulator is UV and weather resistant. Wire can be locked and unlocked from the insulator for easy installation. Insulator is designed for use with both narrow (1.25 lbs/ft) and wide (1.33 lbs/ft) front design posts. The wire is held 1″ from the post. Insulators are sold in bags of 25.